Wireless communication method and device

ABSTRACT

Embodiments of this application provide a wireless communications method and device, to perform appropriate power control on an SRS. The method includes: obtaining a closed-loop power control parameter for a sounding reference signal SRS resource set according to a first uplink signal or a first downlink signal corresponding to the SRS resource set; determining a target transmit power for the SRS resource set according to the closed-loop power control parameter; and sending an SRS to a network device on an SRS resource in the SRS resource set according to the target transmit power.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application is a continuation application of PCT Application No.PCT/CN2017/106933 filed on Oct. 19, 2017, the disclosure of which isincorporated by reference herein in its entity.

TECHNICAL FIELD

This application relates to the communications field, and morespecifically, to a wireless communications method and device.

RELATED ART

In a new radio (New Radio, NR) system, uplink beam management includingtransmit beam management and receive beam management may be performedbased on a sounding reference signal (Sounding Reference Signal, SRS).For the transmit beam management, a terminal sends SRSs in a pluralityof SRS resources by using different beams, and a network side selects atleast one SRS resource based on received signal strengths in a pluralityof SRS resources and indicates the SRS resource to the terminal, so thatthe terminal transmits data by using a beam corresponding to the SRSresource. For the receive beam management, the terminal sends SRSs inone or more SRS resources by using the same beam, and the network sidereceives SRS signals on a plurality of SRS resources based on differentreceive beams, and selects, according to a received signal strengths, areceive beam used to receive data. In an NR system, a transmit antennamay further be selected based on SRSs or channel state information(Channel State Information, CSI) may further be obtained based on SRSs.

The selection of a transmit power of an SRS signal significantly affectsselection of a receive beam and a transmit beam, selection of a transmitantenna, obtaining of channel state information (Channel StateInformation, CSI) or the like in beam management.

Therefore, how to perform power control on an SRS signal is a problemthat urgently needs to be resolved.

SUMMARY

Embodiments of this application provide a wireless communications methodand device, to perform appropriate power control on an SRS.

A first aspect provides a wireless communications method, including:

determining a closed-loop power control parameter for a soundingreference signal SRS resource set according to a first uplink signal ora first downlink signal corresponding to the SRS resource set;

determining a target transmit power for the SRS resource set accordingto the closed-loop power control parameter; and

sending an SRS to a network device on an SRS resource in the SRSresource set according to the target transmit power.

Therefore, in this embodiment of this application, a terminal devicedetermines a closed-loop power control parameter for an SRS resource setaccording to a first uplink signal or a first downlink signalcorresponding to the SRS resource set; and determines a target transmitpower for the SRS resource set according to the closed-loop powercontrol parameter, so that an appropriate transmit power may be selectedto send an SRS.

With reference to the first aspect, in a possible implementation of thefirst aspect, the determining a closed-loop power control parameter foran SRS resource set includes:

determining the same closed-loop power control parameter for SRSresources in the SRS resource set.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, thedetermining a closed-loop power control parameter for a soundingreference signal SRS resource set according to a first uplink signal ora first downlink signal corresponding to the SRS resource set includes:

determining the closed-loop power control parameter for an SRS resourcein the SRS resource set according to the same first uplink signal orfirst downlink signal.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, thedetermining a target transmit power for the SRS resource set includes:

determining the same target transmit power for SRS resources in the SRSresource set.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect,before the determining a closed-loop power control parameter for asounding reference signal SRS resource set according to a first uplinksignal or a first downlink signal corresponding to the SRS resource set,the method further includes:

receiving first indication information of the network device, where thefirst indication information is used to indicate the first uplink signalor the first downlink signal corresponding to the SRS resource set or isused to indicate a resource that carries the first uplink signal or aresource that carries the first downlink signal.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, thefirst uplink signal is an SRS, a physical uplink shared channel PUSCH, aphysical uplink control channel PUCCH, a physical random access channelPRACH, a demodulation reference signal DMRS or a phase trackingreference signal PTRS.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, thefirst uplink signal is an SRS transmitted on one SRS resource in the SRSresource set; or

the first uplink signal is an SRS transmitted on an SRS resourceindicated by latest SRS resource indication information received by theterminal device; or

the first uplink signal is a latest SRS transmitted by the terminaldevice on another SRS resource outside the SRS resource set.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, thatthe first uplink signal is an SRS transmitted on one SRS resource in theSRS resource set includes:

the first uplink signal is an SRS transmitted on an SRS resource withthe lowest SRS resource index in the SRS resource group; or

the first uplink signal is an SRS transmitted on the earliest SRSresource in the SRS resource group.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, theanother SRS resource is an SRS resource used by the network device toobtain channel state information CSI.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, thedetermining a closed-loop power control parameter for a soundingreference signal SRS resource group according to a first uplink signalor a first downlink signal corresponding to the SRS resource groupincludes:

determining a closed-loop power control parameter used to calculate atransmit power of the first uplink signal as the closed-loop powercontrol parameter corresponding to the SRS resource group.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, thefirst downlink signal is a downlink signal used to obtain a path lossestimate for performing power control on the SRS resource group.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, thedownlink signal is a channel state information reference signal CSI-RSor a synchronization signal block.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, thedetermining a closed-loop power control parameter for an SRS resourcegroup according to a first uplink signal or a first downlink signalcorresponding to the SRS resource group includes:

determining an index of a slot in which the first downlink signal istransmitted as an index of a slot in a closed-loop power adjustmentfunction used to perform power control on the SRS resource group.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, theSRS resource group includes a plurality of SRS resources, and thesending an SRS to a network device on an SRS resource in the SRSresource group according to the target transmit power includes:

sending SRSs respectively to the network device on different SRSresources in the SRS resource group according to the target transmitpower and by using different transmit beams or different transmitantennas.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, theSRS resource set is an SRS resource set used for performing uplink beammanagement, used for selecting a transmit antenna or used for obtainingCSI.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, theSRS resource set is used to carry a group of aperiodic SRS transmissionstriggered by one piece of aperiodic SRS trigger signaling; or

the SRS resource set is used to carry a group of continuous SRStransmissions activated by one piece of continuous SRS activationsignaling.

With reference to the first aspect or any possible implementation in theforegoing, in another possible implementation of the first aspect, theclosed-loop power control parameter is a closed-loop power adjustmentvalue, an index of a slot in the closed-loop power adjustment functionor an index of a closed-loop power control process in the closed-looppower adjustment function.

A second aspect provides a wireless communications method, including:

determining a target transmit power for a sounding reference signal SRSresource set by using an index of a time unit occupied by a referenceresource as a closed-loop power control parameter; and

sending an SRS to a network device on an SRS resource in the SRSresource set according to the target transmit power.

Therefore, in this embodiment of this application, a terminal devicedetermines a target transmit power for a sounding reference signal SRSresource set by using an index of a time unit occupied by a referenceresource as a closed-loop power control parameter, so that anappropriate transmit power may be selected to send an SRS.

With reference to the second aspect, in a possible implementation of thesecond aspect, the determining a target transmit power for a soundingreference signal SRS resource set by using an index of a time unitoccupied by a reference resource as a closed-loop power controlparameter includes:

determining the target transmit power for SRS resources in the SRSresource set by using an index of a time unit occupied by the samereference resource as the closed-loop power control parameter.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,the determining a target transmit power for an SRS resource setincludes:

determining the same target transmit power for SRS resources in the SRSresource set.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,before the determining a target transmit power for an SRS resource setby using an index of a time unit occupied by a reference resource as aclosed-loop power control parameter, the method further includes:

receiving first indication information of the network device, where thefirst indication information is used to indicate a reference resourcecorresponding to the SRS resource set.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,the reference resource is one SRS resource in the SRS resource set; or

the reference resource is an SRS resource indicated by latest SRSresource indication information received by the terminal device; or

the reference resource is a latest SRS resource on which the terminaldevice receives an SRS, and the SRS resource is another SRS resourceoutside the SRS resource set; or

the reference resource is the SRS resource set.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,that the reference resource is one SRS resource in the SRS resource setincludes:

the reference resource is an SRS resource with the lowest SRS resourceindex in the SRS resource set; or

the reference resource is the earliest SRS resource in the SRS resourceset.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,if the reference resource occupies a plurality of time units, theterminal device uses an index of the first time unit occupied by thereference resource as the closed-loop power control parameter.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,the another SRS resource is an SRS resource used by the network deviceto obtain channel state information CSI.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,the reference resource is a resource occupied by a downlink signal usedto obtain a path loss estimate for performing power control on the SRSresource set.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,the downlink signal is a channel state information reference signalCSI-RS or a synchronization signal block.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,the SRS resource set includes a plurality of SRS resources, and thesending an SRS to a network device on an SRS resource in the SRSresource set according to the target transmit power includes:

sending SRSs respectively to the network device on different SRSresources in the SRS resource set according to the target transmit powerand by using different transmit beams or different transmit antennas.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,the SRS resource set is an SRS resource set used for performing uplinkbeam management, used for selecting a transmit antenna or used forobtaining CSI.

With reference to the second aspect or any possible implementation inthe foregoing, in another possible implementation of the second aspect,the SRS resource set is used to carry a group of aperiodic SRStransmissions triggered by one piece of aperiodic SRS trigger signaling;or

the SRS resource set is used to carry a group of continuous SRStransmissions activated by one piece of continuous SRS activationsignaling.

A third aspect provides a terminal device, configured to perform themethod in any aspect in the foregoing or any possible implementation ofthe aspect. Specifically, the terminal device includes functionalmodules configured to perform the method in any aspect in the foregoingor any possible implementation of the aspect.

A fourth aspect provides a terminal device, including a processor, amemory, and a transceiver. The processor, the memory, and thetransceiver communicate with each other through internal connectionchannels to transfer control and/or data signals, to enable the networkdevice to perform the method in any aspect in the foregoing or anypossible implementation of the aspect.

A fifth aspect provides a computer readable medium, configured to storea computer program, the computer program including an instruction usedto perform the method in any aspect in the foregoing or any possibleimplementation of the aspect.

A sixth aspect provides a computer program product including aninstruction, where the instruction enables, when being executed on thecomputer, the computer to perform the method in any aspect in theforegoing or any possible implementation of the aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical solutions in the embodiments of thisapplication more clearly, the following briefly describes theaccompanying drawings required for describing the embodiments.Apparently, the accompanying drawings in the following descriptions showmerely some embodiments of this application, and a person of ordinaryskill in the art may still derive other drawings from these accompanyingdrawings without creative efforts.

FIG. 1 is a schematic diagram of a wireless communications systemaccording to an embodiment of this application.

FIG. 2 is a schematic flowchart of a wireless communications methodaccording to an embodiment of this application.

FIG. 3 is a schematic flowchart of a wireless communications methodaccording to an embodiment of this application.

FIG. 4 is a schematic block diagram of a terminal device according to anembodiment of this application.

FIG. 5 is a schematic block diagram of a system chip according to anembodiment of this application.

FIG. 6 is a schematic block diagram of a communications device accordingto an embodiment of this application.

DETAILED DESCRIPTION

The following describes the technical solutions in the embodiments ofthis application with reference to the accompanying drawings in theembodiments of this application. Apparently, the described embodimentsare some but not all of the embodiments of this application. All otherembodiments obtained by a person of ordinary skill in the art based onthe embodiments of this application without creative efforts shall fallwithin the protection scope of this application.

The technical solutions according to the embodiments of this applicationmay be applied to a variety of communications systems, such as a GlobalSystem for Mobile Communications (Global System for MobileCommunications, “GSM” for short) system, a Code Division Multiple Access(Code Division Multiple Access, “CDMA” for short) system, a WidebandCode Division Multiple Access (Wideband Code Division Multiple Access,“WCDMA” for short) system, a General Packet Radio Service (GeneralPacket Radio Service, “GPRS” for short) system, a Long Term Evolution(Long Term Evolution, “LTE” for short) system, an LTE Frequency DivisionDuplex (Frequency Division Duplex, “FDD” for short) system, an LTE TimeDivision Duplex (Time Division Duplex, “TDD” for short), a UniversalMobile Telecommunications system (Universal Mobile Telecommunicationssystem, “UMTS” for short), a Worldwide Interoperability for MicrowaveAccess (Worldwide Interoperability for Microwave Access, “WiMAX” forshort) communications system, a future 5G system (which may also bereferred to as a New Radio (New Radio, NR) system) or the like.

FIG. 1 shows a wireless communications system 100 according to anembodiment of this application. As shown in FIG. 1, the wirelesscommunications system 100 may include a network device 110. The networkdevice 110 may be a device communicating with a terminal device. Thenetwork device 110 may provide communication coverage for a specificgeographic area, and may communicate with a terminal device (forexample, UE) located within the area with coverage. Optionally, thenetwork device 110 may be a base transceiver station (Base TransceiverStation, BTS) in a GSM system or a CDMA system, may be a NodeB (NodeB,NB) in a WCDMA system, or may be an evolved Node B (Evolved Node B, eNBor eNodeB) in an LTE system or a wireless controller in a cloud radioaccess network (Cloud Radio Access Network, CRAN), or the network devicemay be a relay station, an access point, an in-vehicle device, awearable device, a network-side device in a future 5G network, a networkdevice in a future evolved public land mobile network (Public LandMobile Network, PLMN), or the like.

The wireless communications system 100 further includes at least oneterminal device 120 located within a coverage range of the networkdevice 110. The terminal device 120 may be mobile or fixed. Optionally,the terminal device 120 may be an access terminal, user equipment (UserEquipment, UE), a user unit, a user station, a mobile site, a mobilestation, a remote station, a remote terminal, a mobile device, a userterminal, a terminal, a wireless communications device, a user agent, ora user apparatus. The access terminal may be a cellular phone, acordless phone, a Session Initiation Protocol (Session InitiationProtocol, SIP) phone, a wireless local loop (Wireless Local Loop, WLL)station, a personal digital assistant (Personal Digital Assistant, PDA),a handheld device having a wireless communication function, a computingdevice or another processing device connected to a wireless modem, anin-vehicle device, a wearable device, a terminal device in a future 5Gnetwork, a terminal device in a future evolved PLMN, or the like.

Optionally, the terminal device 120 may perform device to device (Deviceto Device, D2D) communication.

Optionally, a 5G system or network may be further referred to as a newradio (New Radio, NR) system or network.

FIG. 1 exemplarily shows one network device and two terminal devices.Optionally, the wireless communications system 100 may include aplurality of network devices and another quantity of terminal devicesmay be included in a coverage area of each network device. This is notlimited in this embodiment of this application.

Optionally, the wireless communications system 100 may further includeanother network entity such as a network controller and a mobilitymanagement entity. This is not limited in this embodiment of thisapplication.

It should be understood that terms “system” and “network” in thisspecification are usually interchangeably used in this specification.The term “and/or” in this specification is only an associationrelationship for describing the associated objects, and indicates thatthree relationships may exist, for example, A and/or B may indicate thefollowing three cases: A exists separately, both A and B exist, and Bexists separately. In addition, the character “/” in this specificationgenerally indicates an “or” relationship between the associated objects.

FIG. 2 is a schematic flowchart of a wireless communications method 200according to an embodiment of this application. The method 200 may beoptionally applied to the system shown in FIG. 1, but is not limitedthereto. The method 200 may be optionally performed by a terminaldevice.

As shown in FIG. 2, the method 200 includes at least some of thefollowing content.

210. The terminal device determines a closed-loop power controlparameter for an SRS resource set according to a first uplink signal ora first downlink signal corresponding to the SRS resource set.

It should be understood that in this embodiment of this application,that the terminal device determines a closed-loop power controlparameter for an SRS resource set may be understood as that the terminaldevice determines a closed-loop power control parameter for an SRSresource in the SRS resource set. In some cases, the two cases areinterchangeable. Optionally, the SRS resource set may include one ormore SRS resources.

Optionally, a network device may configure the SRS resource in the SRSresource set, or a configuration of the SRS resource in the SRS resourceset may be preset.

Optionally, the configuration of each SRS resource in the SRS resourceset may include at least one configuration in the following: an SRSsending period on the SRS resource, an occupied time domain resource, anoccupied frequency domain resource, an occupied spatial domain resource,a used code domain resource, SRS sending times that exists after triggersignaling is received, and/or the like.

Optionally, each SRS resource in the SRS resource set may have anindependent configuration parameter, for example, an SRS sending period,an occupied time domain resource, an occupied frequency domain resource,an occupied spatial domain resource, a used code domain resource, SRSsending times that exists after trigger signaling is received, and/orthe like. These independent configuration parameters may have differentvalues for SRS resources.

Optionally, the SRS resources in the SRS resource set may have a commonconfiguration parameter, for example, an SRS sending period. That is,the SRS resources may have different SRS sending periods.

It should be understood that the SRS resources in the SRS resource setin this embodiment of this application may have the same SRS sendingperiod. In this case, in each SRS sending period, an SRS is sent on allthe SRS resources. The method mentioned in this embodiment of thisapplication may be applied to sending of an SRS resource in each period.

Optionally, the SRS resource set is an SRS resource set used forperforming uplink beam management.

Specifically, the uplink beam management performed based on an SRS mayinclude transmit beam management and receive beam management.

For the transmit beam management, the terminal device sends SRSs in aplurality of SRS resources by using different beams, and the networkdevice selects at least one SRS resource based on received signalstrengths in a plurality of SRS resources and indicates the SRS resourceto the terminal device, so that the terminal device may use a beamcorresponding to the SRS resource to transmit data to the networkdevice.

For the receive beam management, the terminal device may use the samebeam to send an SRS on one or more SRS resources, and the network devicereceives SRS signals on a plurality of SRS resources based on differentreceive beams, and selects, according to a received signal strengths, areceive beam used to receive data.

Optionally, the SRS resource set an SRS resource set used for selectinga transmit antenna.

Specifically, the terminal device uses different transmit antennas tosend SRSs on a plurality of SRS resources, and the network deviceselects at least one SRS resource based on received signal strengths ina plurality of SRS resources and indicates the SRS resource to theterminal device, so that the terminal device may use a transmit antennacorresponding to the SRS resource to transmit data to the networkdevice.

Optionally, the SRS resource set is used for obtaining CSI. The CSI maybe CSI of an uplink channel or CSI of a downlink channel. If the SRSresource set is used for obtaining CSI of a downlink channel, thisapplication may be used for a scenario with uplink and downlinkreciprocity. Optionally, the SRS resource set is used to carry a groupof aperiodic SRS transmissions triggered by one piece of aperiodic SRStrigger signaling.

Specifically, the network device may trigger aperiodic SRS triggersignaling as required. After receiving the aperiodic SRS triggersignaling, the terminal device may use the SRS resource set to transmita group of aperiodic SRS transmissions. The aperiodic SRS triggersignaling may be carried in DCI.

Optionally, the SRS resource set is used to carry a group of continuousSRS transmissions activated by one piece of continuous SRS activationsignaling.

Specifically, the network device may use SRS activation signaling toactivate continuous SRS transmissions. After receiving the SRSactivation signaling, the terminal device may use the SRS resource setto transmit a group of continuous SRS transmissions. The continuous SRStransmissions may be periodic SRS transmissions.

Optionally, the terminal device may determine the same closed-loop powercontrol parameter for SRS resources in the SRS resource set.

It should be understood that, if the same closed-loop power controlparameter is used for each SRS resource, only one closed-loop powercontrol parameter may be determined for one SRS resource set (that is,the closed-loop power control parameter may only need to be determinedonce), and it may be not necessary to determine one closed-loop powercontrol parameter for each resource.

Specifically, for both transmit beam management and receive beammanagement, the terminal device may use the same transmit power for SRSsignals sent on different SRS resources. In this case, the networkdevice may select a more appropriate transmit/receive beam according toreceive signal strength. If the same closed-loop power control parameteris determined for SRS resources in the SRS resource set, the sametransmit power or similar transmit powers may be determined, so that theterminal device may use the same transmit power or similar transmitpowers to send an SRS resource.

Optionally, the closed-loop power control parameter is determined for anSRS resource in the SRS resource set according to the same first uplinksignal or first downlink signal.

Specifically, to determine the same closed-loop power control parameteror similar closed-loop power control parameters, the terminal device maydetermine the closed-loop power control parameter for the SRS resourcesin the SRS resource set according to the same first uplink signal orfirst downlink signal.

Optionally, a closed-loop power control parameter used to calculate atransmit power of the first uplink signal is determined as theclosed-loop power control parameter.

For example, when the first uplink signal is a latest sent PUCCH, aclosed-loop power control parameter used to calculate a transmit powerof the PUCCH may be used as the closed-loop power control parameterdetermined for the SRS resource set.

For example, when the first uplink signal is an SRS transmitted on oneSRS resource in the SRS resource set, a closed-loop power controlparameter may be calculated for the SRS resource, and the calculatedclosed-loop power control parameter is used as the closed-loop powercontrol parameter corresponding to all SRS resources in the SRS resourceset.

For example, when the first uplink signal is an SRS transmitted on anSRS resource indicated by a latest received SRI, the terminal device maydetermine, when receiving the SRI, a closed-loop power control parameterused to send the SRS on the SRS resource indicated by the SRI, and usethe closed-loop power control parameter as the closed-loop power controlparameter corresponding to all SRS resources in the SRS resource set.Certainly, the terminal device may alternatively redetermine, whenreceiving the SRI, a closed-loop power control parameter for the SRSresource indicated by the SRI, and use the calculated closed-loop powercontrol parameter as the closed-loop power control parametercorresponding to all SRS resources in the SRS resource set.

Optionally, before the determining, by the terminal device, aclosed-loop power control parameter for an SRS resource set according toa first uplink signal or a first downlink signal corresponding to theSRS resource set, the terminal device may select the first uplink signalor the first downlink signal used to determine the closed-loop powercontrol parameter.

Certainly, the determining the closed-loop power control parameteraccording to the first uplink signal or the first downlink signalmentioned in this embodiment of this application may be determining theclosed-loop power control parameter according to a resource occupied bythe first uplink signal or the first uplink signal. In this case, itmeans that the terminal device may not need to determine the firstuplink signal or the first downlink signal, but instead uses a resourceof the first uplink signal or the first downlink signal. That is,provided that the resource of the first uplink signal or the firstdownlink signal mentioned in this embodiment of this application is usedto determine the closed-loop power control parameter, the determiningfalls within the protection scope of this embodiment of thisapplication.

In an implementation, the terminal device receives first indicationinformation sent by the network device, where the first indicationinformation is used to indicate the first uplink signal or the firstdownlink signal corresponding to the SRS resource set or is used toindicate a resource that carries the first uplink signal, a resourcethat carries the first downlink signal or a resource on which a firstbeam or a first beam pair is used to receive or send a signal.

Specifically, the network device may indicate, according to an actualcase, the first uplink signal or the first downlink signal used by theterminal device to determine the closed-loop power control parameter orindicate a resource that carries the first uplink signal or a resourcethat carries the first downlink signal.

For example, assuming that the network device requires that the terminaldevice use a relatively high transmit power to send an SRS, an uplinksignal or a downlink signal by using which a higher closed-loop poweradjustment value may be calculated and a resource that carries theuplink signal or downlink signal may be indicated to the terminaldevice.

Optionally, the first indication information and configurationinformation of the SRS resource set may be configured for the terminaldevice together by using radio resource control (Radio Resource Control,RRC) signaling, or the first indication information and triggersignaling or activation signaling of the SRS resource set may beindicated to the terminal device together by using downlink controlinformation (Downlink Control Information, DCI) or a media accesscontrol (Media Access Control, MAC) control element (Control Element,CE).

Optionally, the first indication information is used to indicate one SRSresource in the SRS resource set, so that the terminal device maydetermine the first uplink signal (that is, an SRS sent by using the SRSresource) based on the SRS resource, and determine the closed-loop powercontrol parameter, or directly use the SRS resource (for example, anindex of a slot occupied by the SRS resource) to determine theclosed-loop power control parameter.

Alternatively, the first indication information is used to indicate oneuplink signal or one downlink signal corresponding to the SRS resourceset.

For example, the first indication information indicates an uplink signalcarried in an SRS resource in the SRS resource set or a downlink signalcarried in a CSI-RS resource corresponding to an SRS resource in the SRSresource set, so that the terminal device may determine the closed-looppower control parameter according to a resource (for example, an indexof a slot occupied by the resource) occupied by the uplink signal ordownlink signal.

In another implementation, the first uplink signal or the first downlinksignal corresponding to the SRS resource set is determined according toa first preset relationship. Optionally, the first preset relationshipis preconfigured at delivery.

Optionally, the first preset relationship may indicate which uplinksignal(s) or downlink signal(s) is the first uplink signal or the firstdownlink signal used to determine the closed-loop power controlparameter for the SRS resource set, and the first uplink signal or thefirst downlink signal may be selected for the SRS resource set based onthe relationship.

For example, the first preset relationship indicates that the firstuplink signal used to determine the closed-loop power control parameterfor the SRS resource set is a latest sent physical uplink shared channel(Physical Uplink Shared Channel, PUSCH) or physical uplink controlchannel (Physical Uplink Control Channel, PUCCH) signal, and theterminal device may use the latest sent PUSCH or PUCCH signal as thefirst uplink signal.

For example, the first preset relationship indicates that the firstdownlink signal used to determine the closed-loop power controlparameter for the SRS resource set may be a latest downlink signal usedby the terminal device to determine an uplink transmit beam, and theterminal device may use the latest downlink signal used to determine theuplink transmit beam as the first downlink signal.

Optionally, the closed-loop power control parameter mentioned in thisembodiment of this application may be a closed-loop power adjustmentvalue, an index of a slot in the closed-loop power adjustment functionor an index of a closed-loop power control process in the closed-looppower adjustment function.

Optionally, the terminal device determines an index of a slot in whichthe first downlink signal is transmitted or an index of a slot in whichthe first uplink signal is transmitted as an index of a slot in theclosed-loop power adjustment function used to perform power control onthe SRS resource set.

Specifically, a transmit power of an SRS signal may be determined byusing the following formula:

${{P_{{SRS},c}(i)} = {\min \begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\\begin{matrix}{{P_{{SRS\_ OFFSET},c}(m)} + {10{\log_{10}( {M_{{SRS},c}(i)} )}} +} \\{{P_{0,c}(j)} + {{\alpha_{c}(j)} \cdot {{PL}_{c}(k)}} + {h_{c}( {i,\ 1} )}}\end{matrix}\end{Bmatrix}}},$

where i is an index of a slot, j is an index of an open-loop powercontrol parameter, m is an index of an SRS power offset, and k is anindex of a reference signal RS resource used for path loss estimation.h_(c)(^(i,) 1) is a closed-loop power adjustment function, and 1 is anindex of a closed-loop power control process.

The closed-loop power control parameter mentioned in this embodiment ofthis application may be an index i of a slot or an index 1 of aclosed-loop power control process in the closed-loop power adjustmentfunction h_(c) (i, 1) in the foregoing formula, or may be theclosed-loop power adjustment value obtained by using the closed-looppower adjustment function.

It should be understood that the closed-loop power control parameter inthis embodiment of this application may be an index of a slot or may bean index of another time unit, for example, an index of an orthogonalfrequency division multiplexing (Orthogonal Frequency DivisionMultiplexing, OFDM) symbol or an index of a subframe.

Optionally, the slot mentioned in this embodiment of this applicationmay be a mini slot.

Optionally, the first uplink signal is an SRS, a PUSCH, a PUCCH, aPRACH, a DMRS or a PTRS.

Optionally, the first uplink signal is an SRS transmitted on one SRSresource in the SRS resource set.

In an implementation, the network device may indicate an index of theSRS resource in the SRS resource set, and the closed-loop power controlparameter of the SRS resource may be used for all the other SRSresources in the SRS resource set.

In an implementation, the first uplink signal is an uplink signaltransmitted on an SRS resource with the lowest SRS resource index in theSRS resource set.

In an implementation, the first uplink signal is an uplink signaltransmitted on the earliest SRS resource in the SRS resource set.

Specifically, if indices of the SRS resource in the SRS resource set arearranged in an ascending order of time, the earliest SRS resource in theSRS resource set may be an SRS resource with the lowest index.

Optionally, the first uplink signal is an SRS transmitted on an SRSresource indicated by latest received SRS resource indicationinformation (SRS Resource Indication Information, SRI).

Specifically, before receiving the SRI, the terminal device may transmitan SRS signal in an SRS resource set (where the SRS resource set may bethe resource group mentioned in this embodiment of this application)that includes the SRS resource indicated by the SRI. Each SRS resourcemay optionally be transmitted by using one beam. The SRI is usuallyindicated to the terminal device by using a DCI for schedulingtransmission of uplink data or scheduling transmission of uplink controlinformation. For example, the SRI may be indicated to the terminaldevice by using DCI for triggering the aperiodic SRS.

Optionally, the first uplink signal is a latest SRS transmitted by theterminal device on another SRS resource outside the SRS resource set.

The other SRS resources are SRS resources used by the network device toobtain channel state information (Channel State Information, CSI). Inthis case, the SRS resource in the SRS resource set mentioned in thisembodiment of this application may be used for performing beammanagement, for example, uplink beam management or downlink beammanagement.

Optionally, the first downlink signal is a CSI-RS, a synchronizationsignal, a synchronization signal block, a TRS, a PTRS, a PDSCH, a PDCCHor a DMRS.

For example, the network device may preconfigure a plurality of CSI-RSresources by using higher layer signaling, and then indicate that anindex of a slot of one of the CSI-RS resources is used to determine theclosed-loop power control parameter.

For example, the network device may send a plurality of synchronizationsignal blocks, and indicate an index of a slot used to obtain asynchronization signal block of the closed-loop power control parameter,so that the terminal device may determine the closed-loop power controlparameter based on the index.

Optionally, the first downlink signal is a downlink signal used toobtain a path loss estimate for performing power control on the SRSresource set. In this case, the downlink signal is a channel stateinformation reference signal CSI-RS or a synchronization signal block.

Specifically, during power control, the path loss estimate further needsto be determined. The terminal device may estimate a downlink path lossvalue based on a downlink signal, where the same downlink signal is usedto estimate a downlink path loss value for SRS resources in the SRSresource set, and the downlink signal used to estimate the downlink pathloss value may further be used to determine the closed-loop powercontrol parameter.

Optionally, to calculate a corresponding path loss value for an SRSresource, a CSI-RS may be received on a CSI-RS resource corresponding tothe SRS resource, and a path loss value is calculated based on atransmit power and a receive power of the CSI-RS.

Optionally, CSI-RS resources may have a one-to-one correspondence withSRS resources, or one CSI-RS resource may correspond to a plurality ofSRS resources.

Optionally, a path loss value is estimated according to a receive powerand a transmit power of the first downlink signal, and the estimatedpath loss value is determined as the path loss estimate corresponding tothe SRS resource set.

For example, if the receive power is P1 and the transmit power is P2,the path loss value is denoted as PL=P1/P2. The path loss estimate isusually denoted as dB. That is, PL(dB)=10*lg(P1/P2)(dB).

Optionally, the network device may notify the terminal device of thetransmit power of the first downlink signal in advance by using downlinksignaling. For example, when the first downlink signal is a CSI-RS, thetransmit power may be included in configuration information for sendingCSI-RS resource of the CSI-RS to be notified the terminal device.

Optionally, in addition to a CSI-RS or a synchronization signal block,the first downlink signal may also be another downlink signal, forexample, a physical downlink shared channel (Physical Downlink SharedChannel, PDSCH).

220. The terminal device determines a target transmit power for the SRSresource set according to the closed-loop power control parameter.

It should be understood that in this embodiment of this application,that the terminal device determines the target transmit power for an SRSresource set may be understood as that the terminal device determinesthe target transmit power for an SRS resource in the SRS resource set.In some cases, the two cases are interchangeable.

Optionally, the terminal device determines the same transmit power forthe SRS resources in the SRS resource set.

Optionally, the terminal device determines the target transmit power forSRS resources in the SRS resource set by using the same closed-looppower control parameter.

It should be understood that, if the same transmit power is used for theSRS resources, only one transmit power may be determined for one SRSresource set, and it may be not necessary to determine one transmitpower for each resource.

Optionally, the closed-loop power control parameter may be determinedaccording to the following formula:

${{P_{{SRS},c}(i)} = {\min \begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\\begin{matrix}{{P_{{SRS\_ OFFSET},c}(m)} + {10{\log_{10}( {M_{{SRS},c}(i)} )}} +} \\{{P_{0,c}(j)} + {{\alpha_{c}(j)} \cdot {{PL}_{c}(k)}} + {h_{c}( {i,\ 1} )}}\end{matrix}\end{Bmatrix}}},$

where i is an index of a slot, j is an index of an open-loop powercontrol parameter, m is an index of an SRS power offset, k is an indexof a reference signal RS resource used for path loss estimation.h_(c)(i, 1) is a closed-loop power adjustment function, and 1 is anindex of a closed-loop power control process.

230. The terminal device sends an SRS to a network device on the SRSresource in the SRS resource set according to the target transmit power.

Optionally, the terminal device may send SRSs to the network devicerespectively on different SRS resources in the SRS resource setaccording to the target transmit power and by using different transmitbeams, so that the network device may use the same receive beam toreceive the SRSs respectively on the SRS resources in the SRS resourceset, and select at least one SRS resource based on received signalstrengths in a plurality of SRS resources and indicate the SRS resourceto the terminal device, and the terminal device may transmit data byusing a beam corresponding to the SRS resource.

Optionally, the terminal device may send SRSs to the network devicerespectively on different SRS resources in the SRS resource setaccording to the target transmit power and by using the same transmitbeam, so that the network device receives SRS signals on a plurality ofSRS resources based on different receive beams, and selects, accordingto a received signal strengths, a receive beam used to receive data.

Optionally, the terminal device may send SRSs to the network devicerespectively on different SRS resources in the SRS resource setaccording to the target transmit power and by using different transmitantennas, so that the network device may respectively receive the SRSson the SRS resource in the SRS resource set, and select at least one SRSresource based on received signal strengths in a plurality of SRSresources and indicate the SRS resource to the terminal device, so thatthe terminal device may use a transmit antenna corresponding to the SRSresource to transmit data.

Therefore, in this embodiment of this application, a terminal devicedetermines a closed-loop power control parameter for an SRS resource setaccording to a first uplink signal or a first downlink signalcorresponding to the SRS resource set; and determines a target transmitpower for the SRS resource set according to the closed-loop powercontrol parameter, so that an appropriate transmit power may be selectedto send an SRS.

FIG. 3 is a schematic flowchart of a wireless communications method 300according to an embodiment of this application. The method 300 includesat least some of the following content.

310. A terminal device determines a target transmit power for an SRSresource set by using an index of a time unit occupied by a referenceresource as a closed-loop power control parameter.

It should be understood that the SRS resources in the SRS resource setin this embodiment of this application may have the same SRS sendingperiod. In this case, in each SRS sending period, an SRS is sent on allthe SRS resources. The method mentioned in this embodiment of thisapplication may be applied to sending of an SRS resource in each period.

Optionally, the SRS resource set may be used for performing uplink beammanagement, selecting a transmit antenna or obtaining CSI.

Optionally, the time unit mentioned in this embodiment of thisapplication may be a slot, a mini slot, an OFDM symbol or the like.

Optionally, the target transmit power is determined for SRS resources inthe SRS resource set by using an index of a time unit occupied by thesame reference resource as the closed-loop power control parameter.

Specifically, to determine the same closed-loop power control parameter,the terminal device may use a time unit occupied by the same referenceresource as a closed-loop power control parameter corresponding to theSRS resource in the SRS resource set.

Optionally, before the determining, by a terminal device, a targettransmit power for an SRS resource set by using an index of a time unitoccupied by a reference resource as a closed-loop power controlparameter, the terminal device may determine a reference resource.

In an implementation, the terminal device receives first indicationinformation sent by a network device, where the first indicationinformation is used to indicate a reference resource corresponding tothe SRS resource set.

Specifically, the network device may indicate, according to an actualcase, a reference resource used by the terminal device to determine theclosed-loop power control parameter.

For example, when it is assumed that the network device requires thatthe terminal device use a relatively high transmit power to send an SRS,a reference resource by using which a higher closed-loop poweradjustment value may be calculated may be indicated to the terminaldevice.

Optionally, the first indication information and configurationinformation of the SRS resource set may be configured for the terminaldevice together by using radio resource control (Radio Resource Control,RRC) signaling, or the first indication information and triggersignaling or activation signaling of the SRS resource set may beindicated to the terminal device together by using downlink controlinformation (Downlink Control Information, DCI) or a media accesscontrol (Media Access Control, MAC) control element (Control Element,CE).

In another implementation, a reference resource corresponding to the SRSresource set is determined according to a first preset relationship.Optionally, the first preset relationship is preconfigured at delivery.

Optionally, the first preset relationship may indicate a referenceresource used to determine the closed-loop power control parameter forthe SRS resource set, and a first uplink signal or first downlink signalmay be selected for the SRS resource set based on the relationship.

Optionally, if the reference resource occupies a plurality of timeunits, the terminal device uses an index of the first time unit occupiedby the reference resource as the closed-loop power control parameter.

Optionally, the reference resource mentioned in this embodiment of thisapplication may be an uplink resource or may be a downlink resource.

In an implementation, the reference resource is one SRS resource in theSRS resource set.

For example, the network device may indicate an index of the SRSresource in the SRS resource set, and the index of the slot occupied bythe SRS resource may be used for all the other SRS resources in the SRSresource set to determine the closed-loop power control parameter.

For example, the reference resource is an SRS resource with the lowestSRS resource index in the SRS resource set.

For example, the reference resource is the earliest SRS resource in theSRS resource set.

Specifically, if indices of the SRS resource in the SRS resource set arearranged in an ascending order of time, the earliest SRS resource in theSRS resource set may be an SRS resource with the lowest index.

In an implementation, the reference resource is an SRS resourceindicated by latest SRS resource indication information received by theterminal device.

Specifically, before receiving the SRI, the terminal device may transmitan SRS signal in an SRS resource set (where the SRS resource set may bethe resource group mentioned in this embodiment of this application)that includes the SRS resource indicated by the SRI. Each SRS resourcemay optionally be transmitted by using one beam. The SRI is usuallyindicated to the terminal device by using a DCI for schedulingtransmission of uplink data or scheduling transmission of uplink controlinformation. For example, the SRI may be indicated to the terminaldevice by using DCI for triggering the aperiodic SRS.

In an implementation, the reference resource is a latest SRS resource onwhich the terminal device receives an SRS, and the SRS resource isanother SRS resource outside the SRS resource set.

The other SRS resources are SRS resources used by the network device toobtain channel state information (Channel State Information, CSI). Inthis case, the SRS resource in the SRS resource set mentioned in thisembodiment of this application may be used for performing beammanagement, for example, uplink beam management or downlink beammanagement.

In an implementation, the reference resource is the SRS resource set.

Specifically, the terminal device may use one slot occupied by the SRSresource set as the closed-loop power control parameter of the SRSresource set, and for example, may be the first slot occupied by the SRSresource set in a single period.

In an implementation, the reference resource is a resource occupied by adownlink signal used to obtain a path loss estimate for performing powercontrol on the SRS resource set.

Optionally, the downlink signal is a channel state information referencesignal CSI-RS or a synchronization signal block.

Optionally, the terminal device determines the same transmit power forthe SRS resources in the SRS resource set.

It should be understood that, if the same transmit power is used for theSRS resources, only one transmit power may be determined for one SRSresource set, and it may be not necessary to determine one transmitpower for each resource.

Optionally, the closed-loop power control parameter may be determinedaccording to the following formula:

${{P_{{SRS},c}(i)} = {\min \begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\\begin{matrix}{{P_{{SRS\_ OFFSET},c}(m)} + {10{\log_{10}( {M_{{SRS},c}(i)} )}} +} \\{{P_{0,c}(j)} + {{\alpha_{c}(j)} \cdot {{PL}_{c}(k)}} + {h_{c}( {i,\ 1} )}}\end{matrix}\end{Bmatrix}}},$

where i is an index of a slot, j is an index of an open-loop powercontrol parameter, m is an index of an SRS power offset, k is an indexof a reference signal RS resource used for path loss estimation. h_(c)(i, 1) is a closed-loop power adjustment function, and 1 is an index ofa closed-loop power control process.

320. Send an SRS to a network device on an SRS resource in the SRSresource set according to the target transmit power.

Optionally, the terminal device may send SRSs to the network devicerespectively on different SRS resources in the SRS resource setaccording to the target transmit power and by using different transmitbeams, so that the network device may use the same receive beam toreceive the SRSs respectively on the SRS resources in the SRS resourceset, and select at least one SRS resource based on received signalstrengths in a plurality of SRS resources and indicate the SRS resourceto the terminal device, and the terminal device may transmit data byusing a beam corresponding to the SRS resource.

Optionally, the terminal device may send SRSs to the network devicerespectively on different SRS resources in the SRS resource setaccording to the target transmit power and by using the same transmitbeam, so that the network device receives SRS signals on a plurality ofSRS resources based on different receive beams, and selects, accordingto a received signal strengths, a receive beam used to receive data.

Optionally, the terminal device may send SRSs to the network devicerespectively on different SRS resources in the SRS resource setaccording to the target transmit power and by using different transmitantennas, so that the network device may receive the SRSs respectivelyon the SRS resources in the SRS resource set, and select at least oneSRS resource based on received signal strengths in a plurality of SRSresources and indicate the SRS resource to the terminal device, and theterminal device may use a transmit antenna corresponding to the SRSresource to transmit data.

It should be understood that for the method 300, refer to thedescription of the method 200, for example, the description about thebeam management and the SRS resource set. For brevity, details are notdescribed herein again.

Therefore, in this embodiment of this application, a terminal devicedetermines a target transmit power for a sounding reference signal SRSresource set by using an index of a time unit occupied by a referenceresource as a closed-loop power control parameter, so that anappropriate transmit power may be selected to send an SRS.

FIG. 4 is a schematic block diagram of a terminal device 400 accordingto an embodiment of this application. As shown in FIG. 4, the terminaldevice 400 includes processing unit 410 and a communications unit 420.

Optionally, the processing unit 410 is configured to: determine aclosed-loop power control parameter for a sounding reference signal SRSresource set according to a first uplink signal or a first downlinksignal corresponding to the SRS resource set; and determine a targettransmit power for the SRS resource set according to the closed-looppower control parameter; and the communications unit 420 is configuredto send an SRS to a network device on an SRS resource in the SRSresource set according to the target transmit power.

It should be understood that the terminal device 400 may perform thecorresponding operations performed by the terminal device in the methodshown in FIG. 2. For brevity, details are not described herein again.

Optionally, the processing unit 410 is configured to determine a targettransmit power for a sounding reference signal SRS resource set by usingan index of a time unit occupied by a reference resource as aclosed-loop power control parameter; and the communications unit 420 isconfigured to send an SRS to a network device on an SRS resource in theSRS resource set according to the target transmit power.

It should be understood that the terminal device 400 may perform thecorresponding operations performed by the terminal device in the methodshown in FIG. 3. For brevity, details are not described herein again.

FIG. 5 is a schematic structural diagram of a system chip 500 accordingto an embodiment of this application. The system chip 500 in FIG. 5includes an input interface 501, an output interface 502, a processor503, and a memory 504 that may be connected through an internalcommunication connection line, where the processor 503 is configured toexecute code in the memory 504.

Optionally, when the code is executed, the processor 503 implements themethod performed by the terminal device in the method embodiments. Forbrevity, details are not described herein again.

FIG. 6 is a schematic block diagram of a communications device 600according to an embodiment of this application. As shown in FIG. 6, thecommunications device 600 includes a processor 610 and a memory 620. Thememory 620 may store program code, and the processor 610 may execute theprogram code stored in the memory 620.

Optionally, as shown in FIG. 6, the communications device 600 mayinclude a transceiver 630, and the processor 610 may control thetransceiver 630 to communicate externally.

Optionally, the processor 610 may invoke the program code stored in thememory 620 to perform the corresponding operations of the terminaldevice in the method embodiments. For brevity, details are not describedherein again.

It should be understood that the processor in the embodiments of thisapplication may be an integrated circuit chip and has a signalprocessing capability. During implementation, the steps in the foregoingmethod embodiments may be implemented by using an integrated logiccircuit of hardware in the processor or an instruction in the form ofsoftware. The processor may be a general-purpose processor a digitalsignal processor (Digital Signal Processor DSP), an application specificintegrated circuit (Application Specific Integrated Circuit, ASIC), afield programmable gate array (Field Programmable Gate Array, FPGA) oranother programmable logic device, a discrete gate or transistor logicdevice, and a discrete hardware component. The methods, steps, and logicblock diagrams disclosed in the embodiments of this application may beimplemented or performed. The general-purpose processor may be amicroprocessor or the processor may be alternatively any conventionalprocessor or the like. The steps in the methods disclosed with referenceto the embodiments of this application may be directly performed orcompleted by a decoding processor embodied as hardware or performed orcompleted by using a combination of hardware and software modules in adecoding processor. The software module may be located at arandom-access memory, a flash memory, a read-only memory, a programmableread-only memory or an electrically erasable programmable memory, aregister or another mature storage medium in this field. The storagemedium is located at a memory, and the processor reads information inthe memory and completes the steps in the foregoing methods incombination with the hardware thereof.

It may be understood that the memory in the embodiments of thisapplication may be a volatile memory or a non-volatile memory, or mayinclude both a volatile memory and a non-volatile memory. Thenon-volatile memory may be a read-only memory (Read-Only Memory, ROM), aprogrammable read-only memory (Programmable ROM, PROM), an erasableprogrammable read-only memory (Erasable PROM, EPROM), an electricallyerasable programmable read-only memory (Electrically EPROM, EEPROM) or aflash memory. The volatile memory may be a random-access memory(Random-access memory, RAM) and is used as an external cache. Forexemplary rather than limitative description, many forms of RAMs can beused, and are, for example, a static random-access memory (Static RAM,SRAM), a dynamic random-access memory (Dynamic RAM, DRAM), a synchronousdynamic random-access memory (Synchronous DRAM, SDRAM), a double datarate synchronous dynamic random-access memory (Double Data Rate SDRAM,DDR SDRAM), an enhanced synchronous dynamic random-access memory(Enhanced SDRAM, ESDRAM), a synchronous link dynamic random-accessmemory (Synchlink DRAM, SLDRAM), and a direct Rambus random-accessmemory (Direct Rambus RAM, DR RAM). It should be noted that the memoriesin the systems and methods described herein are intended to include, butare not limited to, these memories and memories of any other suitabletype.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps may be implemented byelectronic hardware, or a combination of computer software andelectronic hardware. Whether the functions are performed by hardware orsoftware depends on particular applications and design constraintconditions of the technical solutions. A person skilled in the art mayuse different methods to implement the described functions for eachparticular application, but it should not be considered that theimplementation goes beyond the scope of this application.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, refer to acorresponding process in the foregoing method embodiments, and detailsare not described herein again.

In the several embodiments provided in the present application, itshould be understood that the disclosed system, apparatus, and methodmay be implemented in other manners. For example, the describedapparatus embodiment is merely exemplary. For example, the unit divisionis merely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented through some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electrical, mechanical or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of this application maybe integrated into one processing unit, or each of the units may existalone physically, or two or more units are integrated into one unit.

When the functions are implemented in a form of a software functionalmodule and sold or used as an independent product, the functions may bestored in a computer-readable storage medium. Based on such anunderstanding, the technical solutions of this application essentially,or the part contributing to the prior art, or part of the technicalsolutions may be implemented in the form of a software product. Thecomputer software product is stored in a storage medium, and includesseveral instructions for instructing a computer device (which may be apersonal computer, a server, a network device, and the like) to performall or some of the steps of the method described in the embodiments ofthis application. The foregoing storage medium includes: any medium thatcan store program codes, such as a USB flash disk, a removable harddisk, a read-only memory (ROM, Read-Only Memory), a random-access memory(RAM, Random-access memory), a magnetic disk, or an optical disk.

The foregoing descriptions are merely specific implementations of thisapplication, but are not intended to limit the protection scope of thisapplication. Any variation or replacement readily figured out by aperson skilled in the art within the technical scope disclosed in thisapplication shall fall within the protection scope of this application.Therefore, the protection scope of this application shall be subject tothe protection scope of the claims.

What is claimed is:
 1. A wireless communications method, comprising:obtaining, a closed-loop power adjustment value for a sounding referencesignal SRS resource set, on an first SRS resource in time in the SRSresource set for transmitting an SRS; determining a target transmitpower for each SRS resource in the SRS resource set according to theclosed-loop power adjustment value for the SRS resource set; andtransmitting the SRS on the SRS resource in the SRS resource setaccording to the target transmit power.
 2. The method according to claim1, wherein the determining a target transmit power for the SRS resourceset comprises: determining the same target transmit power for each SRSresource in the SRS resource set.
 3. The method according to claim 1,wherein the target transmit power is determined according to thefollowing formula: ${P_{{SRS},c}(i)} = {\min \begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\\begin{matrix}{{P_{{SRS\_ OFFSET},c}(m)} + {10{\log_{10}( {M_{{SRS},c}(i)} )}} +} \\{{P_{0,c}(j)} + {{\alpha_{c}(j)} \cdot {{PL}_{c}(k)}} + {h_{c}( {i,\ 1} )}}\end{matrix}\end{Bmatrix}}$ where i is an index of a slot, j is an index of anopen-loop power control parameter, m is an index of an SRS power offset,k is an index of a reference signal RS resource used for path lossestimation. h_(c) (i, 1) is a closed-loop power adjustment function, and1 is an index of a closed-loop power control process.
 4. The methodaccording to claim 1, wherein the SRS resource set comprises a pluralityof SRS resources, and the transmitting an SRS on the SRS resource in theSRS resource set according to the target transmit power comprises:transmitting SRSs to the network device on different SRS resources inthe SRS resource set according to the target transmit power and byrespectively using different transmit beams or different transmitantennas.
 5. The method according to claim 1, wherein the SRS resourceset is an SRS resource set used for uplink beam management, used forobtaining channel state information CSI or used for transmit antennaswitching. SRS resource set
 6. The method according to claim 1, whereinthe SRS resource set is used to carry a group of aperiodic SRStransmissions triggered by one piece of aperiodic SRS trigger signaling;or the SRS resource set is used to carry a group of continuous SRStransmissions activated by one piece of continuous SRS activationsignaling.
 7. A terminal device, comprising a processing unit and acommunications unit, wherein the processing unit is configured to:obtain, a closed-loop power adjustment value for a sounding referencesignal SRS resource set, on an first SRS resource in time in the SRSresource set for transmitting an SRS according to a first uplink signalor a first downlink signal corresponding to the SRS resource set; anddetermine a target transmit power for the SRS resource set according tothe closed-loop power control parameter; and the communications unit isconfigured to send the SRS to a network device on an SRS resource in theSRS resource set according to the target transmit power.
 8. The terminaldevice according to claim 7, wherein the processing unit is furtherconfigured to: determine the same closed-loop power control parameterfor SRS resources in the SRS resource set.
 9. The terminal deviceaccording to claim 7, wherein the processing unit is further configuredto: determine the target transmit power according to the followingformula: ${P_{{SRS},c}(i)} = {\min \begin{Bmatrix}{P_{{CMAX},c}(i)} \\\begin{matrix}{{P_{{SRS\_ OFFSET},c}(m)} + {10{\log_{10}( {M_{{SRS},c}(i)} )}} +} \\{{P_{0,c}(j)} + {{\alpha_{c}(j)} \cdot {{PL}_{c}(k)}} + {h_{c}( {i,\ 1} )}}\end{matrix}\end{Bmatrix}}$ where i is an index of a slot, j is an index of anopen-loop power control parameter, m is an index of an SRS power offset,k is an index of a reference signal RS resource used for path lossestimation. h_(c) (i, 1) is a closed-loop power adjustment function, and1 is an index of a closed-loop power control process.
 10. The terminaldevice according to claim 7, wherein the SRS resource set comprises aplurality of SRS resources, and wherein the processing unit is furtherconfigured to: transmit SRSs to the network device on different SRSresources in the SRS resource set according to the target transmit powerand by respectively using different transmit beams or different transmitantennas.
 11. The terminal device according to claim 7, wherein the SRSresource set is an SRS resource set used for uplink beam management,used for obtaining channel state information CSI or used for transmitantenna switching.
 12. The terminal device according to claim 7, whereinthe first downlink signal is a downlink signal used to obtain a pathloss estimate for performing power control on the SRS resource set. 13.The terminal device according to claim 7, wherein the downlink signal isa channel state information reference signal CSI-RS or a synchronizationsignal block.
 14. The terminal device according to claim 7, wherein theSRS resource set is used to carry a group of aperiodic SRS transmissionstriggered by one piece of aperiodic SRS trigger signaling; or the SRSresource set is used to carry a group of continuous SRS transmissionsactivated by one piece of continuous SRS activation signaling.
 15. Asystem chip, comprising: a processor configured to: obtain, aclosed-loop power adjustment value for a sounding reference signal SRSresource set, on an first SRS resource in time in the SRS resource setfor transmitting an SRS; determine a target transmit power for each SRSresource in the SRS resource set according to the closed-loop poweradjustment value for the SRS resource set; and transmit the SRS on theSRS resource in the SRS resource set according to the target transmitpower.